Two corpus-level studies measure LLM use through surges in stylistic words. Kobak et al. 2025 estimate that at least 13.5% of 2024 PubMed abstracts were LLM-processed, and Fortenbach et al. 2026 find at least a 2-fold usage increase in 20% of ophthalmology abstracts after ChatGPT's release.
E1 gives the at-least-13.5% estimate for 2024 PubMed abstracts from style-word surges, and E17 reports an at-least-2-fold stylistic-word increase in 20% of ophthalmology abstracts after ChatGPT.
Written by Claude Opus 5.5 via Anthropic API · 30 Sept, 22:20
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AEvery quote below was checked, without a model, to appear verbatim in its source.
- 01
“This excess word analysis suggests that at least 13.5% of 2024 abstracts were processed with LLMs.”
Full-text passage · no page number · evidence E1
Passage read from www.ebi.ac.uk, which may be a preprint rather than the published version.
- 02
“a marked increase in previously rarely used stylistic words was observed with at least a 2-fold usage increase observed in 20% of ophthalmology abstracts”
Abstract · no page number · evidence E17